If i have a canon 85mm/1.2L, a 7D body and a 5D body. A tripod at 0 metres, a human subject (looking straight into the camera) at 3 metres and a "bokeh friendly" ....christmas tree at 10 metres.

Shooting with either camera (wide open with focus on subjects eyes) would result in the pretty much the same quality of out-of-focusness on the xmas tree (and the area in focus on the subject will be the same - lets say the eyes and ears are both sharp)? The only difference being the 7D would result in a image that was just like you had cropped an image from the 5D i photoshop (apart from the change in mpix)? Would I be right in making this statement?

In your above example - that is all true. But if you don't crop the 5D image (why waste all those pixels?) and just step forward to get the same framing as the 7D, you are at a closer focus distance, which GREATLY decreases the DOF and, with the Canonball F1.2, your bokeh will be very pronounced and creamy indeed.